After a successful sting operation,NCIS Los Angeles Seasons 1-7 DVD three FBI agents are killed in a sudden explosion, resulting in OSP being assigned to investigate. Upon investigating, they learn that the agents were killed by a hidden bomb and that the attack isn't the only one - leaving the team racing against the clock to identify where the second attack is being held. Meanwhile, for the investigation,Chris O'Donnell as G. Callen, Special Agent in Charge and undercover operative attached to the Office of Special Projects Placed in the foster system at a young age, G. does not even know his own first name, but is determined to find out about his family, and in turn, himself. Living somewhat of a nomadic nature, Los Angeles is G's most stable home. He is partners with Sam Hanna.